The present invention relates to a replaceable printer ink ribbon supply roll and, more particularly, to a replaceable printer ink ribbon supply roll including a sensor hub for identifying the print ribbon type.
Ink ribbon cartridges that are used in thermal printers are well known in the art. The cartridges usually include a casing or housing and at least one spool having a ribbon wound on the spool. The spool or supply roll rotates as the ribbon is fed through the printer during the printing operation.
Various kinds of ink ribbons with different characteristics are available. It is important to accurate and proper printer operation that the correct type of ribbon is inserted into the printer and that the printer itself is properly configured for a particular ribbon type. Exemplary ribbons include waxed ribbons, dye sublimation ribbons, or resin ribbons. Moreover, each of the ribbon types has variations that can be separately identified, including color.
Various ribbon identification devices have been proposed. For example, a device for identifying an ink ribbon cartridge used in a printer is shown in U.S. Pat. No. 5,385,416, which utilizes a photosensor to detect information marks recorded on a ring that has relative motion with respect to the ribbon spool or roll. The identifying information is sensed when the thermal printing head has moved to its operative position.
The present invention is, in particular, an improvement on another ribbon identification device described in U.S. Pat. No. 5,755,519, the disclosure of which is hereby incorporated by reference. In this patent, identifier indicia carried on a ribbon supply roll placed for indicating the type of ribbon that is on the supply roll is moved past a sensor during use to determine ribbon type or other coded information. In particular, one end of the supply roll is provided with a core insert or hub member that has a plurality of annularly spaced identifier indicia including sensor activating components. These components move past a stationary sensor to provide a signal from the sensor. Axially-extending openings or bores in the ribbon supply roll core receive pins as inserts that identify characteristics of the print ribbon.
Because the pins are removable, however, the pins cannot be reliably secured in the identifying hub member and may fall out during shipping, thereby rendering the ribbon useless. In addition, the manufacturing method is performed in multiple steps, requiring additional manufacturing time, thereby increasing manufacturing costs. One of these multiple steps is operator insertion of the pins into the hub, which process is susceptible to human error. Even a single misplaced pin would render the product unusable.